For example, Japanese Laid-Open Patent Publication No. 2005-115494 discloses a technique, which relates to a business process tracking apparatus, for enabling to track a flow of a business process including plural applications executed over different business systems, without changing an existing system. Specifically, an event management apparatus collects event data that an event extractor of the respective business systems extracted based on event extraction definition, and queues the event data into an event queue. An event association unit gathers, for each business data unit, the event data to carry out association between the business data, and stores results into an event management database (DB). When a search condition is inputted from a user terminal, an output unit searches the event management DB according to the search condition, and outputs and displays the association between the business data in a tree format to the user terminal.